Control device



Nov. 8, 1960 J. R. BOYKIN CONTROL DEVICE Filed June 4. 1945 WITNESSES: 0%; 74M

INVENTOR ATTORN Y Jo/m 55 mm.

United States Patent CONTROL DEVICE John R. Boykin, Baltimore, Md., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed June 4, 1945, Ser. No. 597,457

7 Claims. (Cl. 102-702) My invention relates to control devices and, in particular, to devices to be mounted on bombs, projectiles, rockets and the like, and designed to act as antennas or radiators of electromagnetic energy in conjunction with radio apparatus housed within the bomb, or the like.

Many pieces of equipment have been developed in recent years in which bombs, projectiles or other moving vehicles, are provided with radio apparatus which either radiate or receive energy from electromagnetic fields external to the vehicle and employ it in conjunction with radio apparatus housed within the vehicle. In such cases, it is necessary to provide some form of antenna on which the radiated or received electromagnetic waves may react. However, the high speeds with which the ve hicles travel through the air imposes many mechanical stresses on these antennas and the design of an antenna, which will be mechanically stable and able to resist the stresses of the air streams flowing past the surface of the vehicle, has proved to constitute a problem of grave difiiculty.

One object of my invention is, accordingly, to provide a form of antenna or electrical radiator suitable for mounting on bombs, or other rapidly moving projectiles, or vehicles and which shall produce fields of radiated electrical energy having a desirable space distribution about the moving vehicle.

Another object of my invention is to provide a structure suitable for radio antennas mounted on bombs, projectiles, or other vehicles, adapted to move at high velocity through the air.

Still another object of my invention is to provide a structure for radio antennas for bombs, projectiles, or other vehicles, intended for rapid motion through the air, which shall be mechanically stable against vibration and likewise strong enough to withstand the stresses imposed by movement of the vehicle.

Still another object of my invention is to provide a form of electromagnetic radiator for bombs, projectiles, or other rapidly moving vehicles such as mortar shells, which shall be capable of withstanding therapid acceleration imparted to the projectile and which shall produce an intense electromagnetic radiation field at points located in the longitudinal axis of the shell.

A still further object of my invention is to provide a bomb, shell or other vehicle intended for rapid motion through the air, with means for triggering an electric control circuit when the projectile closely approaches the material, such as a target.

Still other objects of my invention will become apparent upon reading the following description, when taken in connection with the accompanying drawings, in which:

Figure 1 is a figure, partly schematic and partly a sectional elevation, illustrating an antenna structure suitable for bombs and constituting one modification of my invention; and

Fig. 2 is a figure of similar nature illustrating another modification of my invention.

2,959,128 Patented Nov. 8, 1960 Fig. 3 is a figure of similar nature illustrating a still different modification of my invention.

Referring in detail to Figure 1, the reference numeral 1 indicates the walls of a bomb, projectile, or other vehicle intended for rapid movement through the air. In accordance with conventional practice, the structure 1 is tapered at its front end, and may be provided with a cap 2 of some suitable insulating material, of which many are well-known in the art. Inside the walls of the structure 1 is located an electronic apparatus of any desired type which is to receive from, or alternatively transmit to, points outside the enclosure 1, electromagnetic waves. For example, the electronic apparatus may be an oscillation generator 3, of a type well-known in the art, having a thermionically emissive cathode 4, an anode 5, and a control electrode 6. To illustrate one use of such an apparatus, it may be desired to project to points along the longitudinal axis of the projectile 1 a high-frequency electromagnetic field. In order to do this, electrical oscillations generated by the oscillation generator 3 are impressed upon an antenna system 7, 8, mounted on the exterior of the projectile 1. A convenient circuit for generating such oscillations is illustrated, although many others may be used, and comprises a supply of current from a positive terminal of a voltage source to the anode 5 through a transformer primary 9 and impedance 10. The negative terminal of the voltage source just mentioned is preferably connected to the walls of the projectile 1. A resistor 11 connects the control electrode 6 to the cathode 4. The transformer winding 9 may energize any desired load or control circuit (not shown) through a secondary winding 9A which may be tuned to respond to the beat note of reflected waves incident upon antenna 7, 8.

The components 7, 8 of the antenna system each comprises a piece of conducting rod or strap having one end welded, or otherwise securely fastened, to the wall of through the walls of the cap 2. The two ends of the members 7 and 8 are respectively connected through condensers 13, 14 to the control electrode 6 and the anode 5 of the oscillation generator 3. The distance between the members 7 and 8 is preferably small compared to a quarter wave length by the frequency generated by the oscillation generator 3. Under such circumstances, the electromagnetic field intensity produced by the members 7 and 8, at points along the projected axis of the projectile 1, will be additive and a very substantial field intensity may readily be produced at such points.

Provided the members 7 and 8 are made of suitably thick and wide material, they form a structure which is readily made rigid and has little tendency toward -me-- chanical vibration or breakage by sudden acceleration of the projectile 1.

Turning now to Fig. 2, there is shown a modification of my invention in which the antenna, or electric radiator, comprises a piece of strap conducting material bent around in the manner indicated so that its opposite ends may be secured by bolts 12 to the cap portion 2 of a projectile 1, which is similar in general structure to that already illustrated in Fig. 1. Within the projectile 1 is positioned an electronic device comprising a tube 22 having an anode 23, a cathode 24 and a control electrode 25, all of a form well-known in the electronic art. The tube 22 has its cathode 24 connected to its anode 23 through a voltage source 26 and a coupling winding 27 of a form well-known in the electronic art. A trigger circuit 28 may be coupled by any means Well-known in the electronic art,

for example, by electromagnetic induction, with the circuit of the anode 23. The circuit 28 may, for example,

constitute a portion of a trigger circuit of a relay, of any type well-known in the art, adapted to detonate a charge of explosives carried by the projectile 1. The cathode 24 is connected to the grid 25 through a conventional grid resistor 29.

The opposite ends of the antenna 21 are respectively connected through capacitors 31 and 32, to the control electrode 25 and the anode 23. When arranged as so far described, the voltages generated in the antenna 21 by electromagnetic waves incident thereon are obviously capable of exciting the tube 22 and producing amplified control effects in apparatus connected to its output circuit.

Fig. 3 shows an arrangement well adapted to permit the projectile 1 to be exploded by the reactions on a magnetic field set up by the projectile itself of objects into proximity with which the projectile moves. Thus, the projectile may have mounted upon it a permanent magnet to set up such a magnetic field; or alternatively such a magnetic field may be set up by current flowing from a direct-current source 33 through a suitable control rcsistor 34 and through a winding 35 mounted on the nose 2 of the projectile preferably with its axis aligned with the axis thereof. The terminals of winding 35 are coupled through a capacitor 31 across the grid-to-cathode circuit of an electron tube 22 similar in connections and function to the tube 22 of Fig. 2.

When the projectile 1 approaches a body having any substantial conductivity, a magnetic field set up by the projectile itself will induce eddy currents in such a conductive body, which in turn, will react to induce current in the coil 35 which acts as an antenna and impresses voltages on the tube 22. The voltages thus induced on the control electrode 25 of the tube 22 may be made sufficient to cause sufficient current flow through the winding 27 and the trigger circuit 28 to detonate an explosive charge within the projectile 1. The detonation of an explosive is mentioned merely as one possible way of employing the reactions in the output circuit of the tube 22, and such reactions may be employed for any other desired control purposes.

I claim as my invention:

1. In combination with a projectile intended to move rapidly through the air, an antenna comprising a conducting strap having one end fastened to the wall of the projectile, an insulating wall portion for said projectile, and means for fastening the other end of said strap to said insulating wall portion.

2. In combination with a projectile intended for rapid movement through the air, an antenna comprising a piece of conducting strap material bent into a loop and shaped so that its two ends may be fastened to points spaced apart on the exterior of said projectile, and means for fastening said ends to said points.

3. In combination with a projectile intended to move rapidly through the air and having separate wall portions, one of conducting material and the other of insulating material, a pair of antenna elements each comprising a piece of strap material bent into a curved loop, one end of said loop being fastened to said conducting wall portion and the other end of said loop being fastened to said insulating wall portion.

4. In combination with a projectile having an axis of symmetry intended to move rapidly through the air in a direction parallel to said axis, an antenna comprising a conducting strap having one end fastened to the wall of the projectile, an insulating wall portion for said projectile, and means for fastening the other end of said strap to said insulating wall portion, said strap lying substantially in a plane passing through said axis.

5. In combination with a projectile having an axis of symmetry intended for rapid movement through the air in a direction parallel to said axis, an antenna comprising a piece of conducting strap material bent into a loop and shaped so that its two ends may be fastened to points spaced apart on the exterior of said projectile, said strap lying substantially in a plane passing through said axis, and means for fastening said ends to said points.

6. In combination with a projectile having an axis of symmetry intended to move rapidly through the air in a direction parallel to said axis and having separate wall portions, one of conducting material and the other of insulating material, a pair of antenna elements each comprising a piece of strap material bent into a curved loop, one end of said loop being fastened to said conducting wall portion and the other end of said loop being fastened to said insulating wall portion, said strap lying substantially in a plane passing through said axis.

7. In combination with a projectile having an axis of symmetry intended for rapid movement through the air in a direction parallel to said axis, an antenna comprising a piece of conducting strap material bent into a loop and shaped so that its two ends may be fastened to points spaced apart on the exterior of said projectile, said strap lying substantially in a plane passing through said axis, means for fastening said ends to said points, and means on said projectile for generating electrical oscillations and for energizing said antenna therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,523,798 Benson Jan. 20, 1925 1,623,475 Hammond Apr. 5, 1927 2,182,484 Mills Dec. 5, 1939 2,276,935- 'Como Mar. 17, 1942 2,388,625 Wagenknecht Nov. 6, 1945 2,400,551 Hings May 21, 1946 2,402,459 Smith June 18, 1946 FOREIGN PATENTS 91,592 Sweden Feb. 24, 1938 539,224 Great Britain Sept. 2, 1941 546,488 Great Britain July 16, 1942 

